1. Field of the Invention
This invention relates to a new form of presentation improved in many respects for lubricants and lubricant systems which are added in geological exploration to corresponding water-based drilling fluids and/or other water-based working fluids from this field. In the following, the invention is described with reference to pure water-based drilling fluids and drilling muds based thereon. However, the fluids according to the invention are by no means confined to this particular application. On the contrary, the invention also encompasses corresponding fluids for tackling problems arising out of differential sticking, more particularly spotting fluids and fluids used for workover, stimulation and comparable applications in geological drilling.
2. Discussion of Related Art
In the relevant technology of the geological exploration of, for example, oil and/or gas occurrences, there are three basic types of auxiliary fluids used in practice, more particularly corresponding drilling muds: oil-based systems which generally comprise a continuous oil phase mixed with a disperse water phase in the form of so-called w/o invert muds, water-based oil/water systems in which the aqueous phase with its dissolved and dispersed auxiliaries forms the continuous phase and the oil phase is dispersed therein in the form of a fine emulsion and, finally, pure water-based drilling fluids. So far as the pure water-based drilling fluids in particular are concerned, proposals have recently been taken up again to use purely aqueous systems based on soluble alkali metal silicates which are also known as waterglasses or waterglass-based systems.
The use of components with a pronounced lubricating effect in drilling muds can be extremely important. Thus, the rate of advance can be significantly accelerated so that the time required to drill to predetermined depths can be shortened and problems, for example arising out of differential sticking, are prevented or at least suppressed. General expert knowledge is relevant in this regard, cf. for example the book by George R. Gray and H. C. H. Darley entitled "Composition and Properties of Oil Well Drilling Fluids", 4th Edition, 1980/81, Gulf Publishing Company, Houston and the extensive scientific and patent literature cited therein and the manual entitled "Applied Drilling Engineering" by Adam T. Borgoyne, Jr. et al., First Printing Society of Petroleum Engineers, Richardson, Tex. (USA).
The use of auxiliary components with a lubricating effect can be of particular importance for water-based working fluids, more particularly corresponding water-based drilling muds. The following specific problem inter alia arises in this regard: auxiliary components with a pronounced lubricating effect which are insoluble in the aqueous system--normally corresponding components of organic origin--should consist of very fine particles and should be uniformly dispersed in the drilling fluid. This applies in particular to their primary incorporation in the drilling mud for periodically or continuously increasing the amount of drilling mud which is increasingly demanded by the rate of advance and by the increasing size of the borehole to be filled with the drilling mud.
The problem addressed by the present invention is in particular to provide a new form of presentation in which organic lubricants or lubricant systems are stably and very finely dispersed in a continuous aqueous phase. The incorporation of such lubricant systems in water-based auxiliary fluids, for example of the drilling mud type, and the immediate very fine homogenization of the organic phase in the water-based system are thus made possible. At the same time, the effect of the organic based lubricants is enhanced, at least in the early stages of their use.